also show fingertips when capturing screen

On iOS 11 and higher it's possible to record the screen on the device itself. Making touches visible in that scenario is also very useful.

MBFingerTipWindow.m

@@ -92,15 +92,23 @@ - (void)MBFingerTipWindow_commonInit
  name:UIScreenDidDisconnectNotification
  object:nil];
 
+ if (@available(iOS 11.0, *))
+ [[NSNotificationCenter defaultCenter] addObserver:self
+ selector:@selector(screenCaptureChanged:)
+ name:UIScreenCapturedDidChangeNotification
+ object:nil];
+
  // Set up active now, in case the screen was present before the window was created (or application launched).
  //
  [self updateFingertipsAreActive];
 }
 
 - (void)dealloc
 {
- [[NSNotificationCenter defaultCenter] removeObserver:self name:UIScreenDidConnectNotification  object:nil];
+ [[NSNotificationCenter defaultCenter] removeObserver:self name:UIScreenDidConnectNotification object:nil];
  [[NSNotificationCenter defaultCenter] removeObserver:self name:UIScreenDidDisconnectNotification object:nil];
+ if (@available(iOS 11.0, *))
+ [[NSNotificationCenter defaultCenter] removeObserver:self name:UIScreenCapturedDidChangeNotification object:nil];
 }
 
 #pragma mark -
@@ -156,12 +164,12 @@ - (UIImage *)touchImage
 
 - (void)setAlwaysShowTouches:(BOOL)flag
 {
- if (_alwaysShowTouches != flag)
- {
- _alwaysShowTouches = flag;
+ if (_alwaysShowTouches != flag)
+ {
+ _alwaysShowTouches = flag;
 
  [self updateFingertipsAreActive];
- }
+ }
 }
 
 #pragma mark -
@@ -177,6 +185,11 @@ - (void)screenDisconnect:(NSNotification *)notification
  [self updateFingertipsAreActive];
 }
 
+- (void)screenCaptureChanged:(NSNotification *)notification
+{
+ [self updateFingertipsAreActive];
+}
+
 - (BOOL)anyScreenIsMirrored
 {
  if ( ! [UIScreen instancesRespondToSelector:@selector(mirroredScreen)])
@@ -186,6 +199,10 @@ - (BOOL)anyScreenIsMirrored
  {
  if ([screen mirroredScreen] != nil)
  return YES;
+
+ if (@available(iOS 11.0, *))
+ if ([screen isCaptured])
+ return YES;
  }
 
  return NO;